1. AMMONIA AMMONIA PROCES PROCESS S The feed to the process process is nitrogen, hydrogen, hydrogen, and a small amount amount of carbon dioxide dioxide (left over over from the process to make the hydrogen). The process feed is mixed with a recycle stream, heated to the reactor temperature, and sent to the reactor. reactor. The feed to the reactor is roughly a 3: mixture of hydrogen and nitrogen, with some ammonia, too. The reaction is limited by e!uilibrium considerations, so the conversion is not known. "ou must determine it by solving the e!uilibrium e!uation (using #$ibbs). %n this example, the pressure is high because that favors the reaction. The temperature is also high in order to get a fast reaction, even though this limits the conversion in the reactor. reactor. The output from the reactor is cooled and sent to a vapor &li!uid separator (this example uses 'lash), where the temperature is lowered. Thus, most of the ammonia condenses and is removed as a li!uid. The vapor is recycled and is sent through a compressor to get the pressure back to the desired pressure. small part of the recycle stream is bled o* as a purge stream to prevent the buildup of impurities. %n this example, you will take an input stream to the process (at + -' and 3 psia) of: nitrogen, lbmolh/ hydrogen, 3 lbmolh/ ammonia, / and carbon dioxide, dioxide, lbmolh. The inlet stream is compressed to to 0 psi with an isentropic compressor compressor.. The stream is mixed with the recycle stream and heated to 1 -', the reactor temperature. %n the reactor, there is a pressure drop of 3 psi. The outlet is cooled to + -' and the li!uid and vapor phases are separated. The vapor phase goes to recycle, and . percent of it is used as purge. recycle compressor then compresses the rest from 312 to 0 psia. %n a real process, the heat transfer to preheat the feed to the reactor uses the euent from the reactor, usually inside the same vessel. %n process simulators, though, it is useful to begin as shown in the 'igure to help convergence. 4#T5 4#T5 thermodynamics was chosen and is 6usti7ed a posteriori.
2.- BENZENE PROCESS 8imulate the ben9ene process using spen lus. Take the feed at room temperature and atm. ;ompress it to 3< atm. reheat the feed to the reactor to << -; and cool the euent. =odel the reactors as #8toic reactors, and keep the hydrogenmethane separations as simple splitters/ model the other separations using distillation towers. "ou will have to decide on the number of stages and re>ux ratio, and using ?8T@A 7rst might be useful. The process for making ben9ene is described below and illustrated in 'igure, and you are to make mass balances. (Bydrocarbon rocessing, 12
B"#%"#" Proc"&& The reactions and their conversion per pass are:
The output from the reactor contains all the components, and the hydrogen and toluene are recycled, the methane is removed from the process, and the ben9ene and xylenes are removed from the process. The vapor pressures of the components at -; are: ben9ene, 2< mmBg/ toluene, mmBg/ xylenes, 0.+ &D.D mmBg/ trimethylben9ene, . mmBg. separation system is used that removes the hydrogen and methane 7rst, then separates the ben9ene, then the toluene, and then the trimethylben9ene. The hydrogen and methane should be somewhat separated (to recover the hydrogen, which is recycled) and the toluene is recycled. %n the separators, use splits of 11.1 percent of the light component out of the top and only . percent of the next heavier component. Ase splits of percent for components lighter than the light key and percent for components heavier than the heavy key. Ase $oal
8eek or 8olver to ad6ust the hydrogen makeup feed to insure the proper amount of hydrogen enters the reactor (necessary for the catalyst). P.E. '2 ( -2)* +C, P.E. MEANO ( -1/
+C, P.E. BENCENO ( 0.1 +C, P.E. O3ENO ( 11. +C, P.E. ORO4IENO ( 1// +C , P.E. 1,2,*-RIMEIBENCENO ( 17 +C
I# th" 5"" &tr"a6: ol$"#" ( 1 6ol8h 6ol8h of "#%"#" ;;< p$r"
It i& r"9$ir" to otai#: /
*.- E'= C'OR=>E PROCESS 8imulate the ethyl chloride process using spen lus. The feed streams are at room temperature and psia and they are compressed to 1< psia. reheat the feed to the reactor to + -' and cool the euent. =odel the reactors as #8toic reactors. Take the euent from the 7rst reactor, cool it, and send the li!uid to the product stream. ;ompress the gases to D< psia, and heat them to 3< -' (if needed). 5ower the pressure and cool the euent from the second reactor and separate the li!uid and vapor. #ecycle the vapor and send the li!uid to the product stream. "ou will have to decide on the cooling temperature to use in the vapor & li!uid separators. Ethyl chloride is manufactured in an integrated process/ see 'igure, (8tirling,1+0, p. 2). ;omplete a mass balance for this process. Ethane reacts with chlorine to make ethyl chloride and hydrogen chloride, and ethylene reacts with hydrogen chloride to form ethyl chloride.
Ethyl chlori" proc"&&
The process is feed with three streams: ethane, ethylene, and chlorine. h" "tha#" a# "thyl"#" &tr"a6& ha?" th" &a6" 6olar @ow rat" , and th" ratio of chlori#" to "tha#" pl$& "thyl"#" i& 1.) . The ethaneethylene stream also contains .< percent acetylene and carbon dioxide. 5or thi& prol"6, $&t $&" 1.) p"rc"#t caro# ioi". ) The feed streams are mixed with an ethylene recycle stream and go to the 7rst reactor (chlorination reactor) where th" "tha#" r"act& with chlori#" with a ;) p"rc"#t co#?"r&io# p"r pa&& . The product stream is cooled and ethyl chloride is condensed and separated. ssume that all the ethane and ethyl chloride go out in the condensate stream. The gases go to another reactor (hydrochlorination reactor) where the reaction with ethylene takes place with a ) p"rc"#t co#?"r&io# p"r pa&&. The product stream is cooled to condense the ethyl chloride, and the gases (predominately ethylene and chlorine) are recycled. A p$r!" or l"" &tr"a6
ta"& oD a fractio# of th" r"cycl" &tr"a6 $&" 1 p"rc"#t. ;omplete the mass balance for this process.
P.E. 'Cl ( /0 +C, P.E. Ethyl Chlori" ( 12.* +C, P.E. Chlori#" ( -*/ +C, ( -0; +C, P.E. Ethyl"#" ( -1/ +C
I# th" "tha#" a# "thyl"#" &tr"a6:
P.E. Etha#"
th" "tha#" ( 1 l6ol8h.
It i& r"9$ir" to otai#: 100 l6ol8h of Ethyl chlori" ;0< p$r"
/.- FIN= C'ORI>E PROCESS 8imulate the vinyl chloride process using spen lus. Take the feed at room temperature and psia. Cperate the direct chlorination reactor at D< -; and ux ratio/ using ?8T@A 7rst might be useful. The oxychlorination reactor operates at -; and 0 ka. @ash the euent from the oxychlorination reactor with water to remove contaminants and then remove the water and light gases in a distillation column. The ethylenedichloride must be dry (F ppm) before going to the furnace. The stream then goes to a distillation column where the ethylenedichloride is puri7ed (G 11.
takes place with essentially percent conversion of the limiting reagent. The selectivity to ethylenedichloride is 11 percent with the main byproduct (and the only one considered here) being ,,Jtrichloroethane. Ethylene and oxygen are mixed with a hydrogen chloride recycle stream and sent to an oxychlorination reactor, where the reaction
takes place with a conversion of 1D percent for ethylene and ethylenedichloride selectivities of 1< percent. Bere you can assume the byproduct is all ,,Jtrichloroethane. The output from
the direct chlorination reactor is sent to a distillation tower where the heavy components are distilled o*. The light components are sent to a furnace where a pyrolysis reaction takes place:
The feed to the furnace must be very pure (11.< percent ethylenedichloride) to achieve good cracking. The output is !uenched. The li!uid is the vinyl chloride product and the vapor is hydrogen chloride, which is recycled to the oxychlorination reactor. The output from the oxychlorination reactor is cooled to remove the li!uid (mostly water). vent is used to remove light gases. The remainder goes to a distillation column where ethylenedichloride is the heavy component (and is sent to the furnace) and the light components are recycled to the oxychlorination reactor. The feed to the oxychlorination reactor uses a slight excess of oxygen and ethylene to ensure that all the hydrogen chloride reacts. The feed to the direct chlorination reactor is stoichiometric.
Iinyl chloride process
).Bow does the process in roblem 0 change if the furnace is run at the high pressure (0 ka)K
AREA E'ANO PROCESS 8imulate the ethanol process using spen lus. The feed streams are at atm and room temperature, but the reactor operates at 1D psia and <2 -'. Thus, you must heat the reactor feed, and after the reaction occurs you must cool the product. The 7rst splitter is a vapor & li!uid separator (you choose the temperature that will separate ethanol from ethylene), and the remaining splitters are distillation columns. "ou will have to decide on the number of stages and re>ux ratio/ using ?8T@A 7rst might be useful. 8ynthetic ethanol is made by vaporJphase hydration of ethylene, as shown in 'igure. =ake a mass balance of this process.
@ater and ethylene are mixed with a recycle stream and sent to a reactor where the reaction takes place (< percent conversion per pass). The ethylene feed is 12 percent ethylene but also contains acetylene (.1 percent) and inert gases (. percent). The acetylene reacts with water, too, forming acetaldehyde (< percent conversion per pass).
The reactor euent is cooled to remove the li!uids (ethanol, acetaldehyde, water). The gases (ethylene, acetylene, and inert gases) are recycled, but a purge stream is needed to remove the inert gases. ssume perfect splits. d6ust the fraction purged to keep the ratio of inert gas to ethylene in the stream fed to the reactor at .0, and feed enough water to the process to make the molar ratio of water to ethylene .D in the stream into the reactor. 8eparate the li!uids into relatively pure component streams, 7rst removing D percent of the water, then the acetaldehyde, then purifying the ethanol to 13 percent by removing water.
Etha#ol proc"&&
I# th" "thyl"#" pl$& ac"tyl"#" &tr"a6:
th" "thyl"#" ( /1;./ 6ol8h.
It i& r"9$ir" to otai#: /7.) 6ol8h of Etha#ol ;*< p$r"
AREA
PRO>3CCIGN >E C3MENO El cumeno (;DB<;3B2) se produce por la reacciLn del benceno y el propileno en un reactor catalMtico de lecho 76o. N
∆
B-r (22-') O J31 < PtulbJmol.Q. 8e alimenta al reactor
un lM!uido !ue contiene 2u6o lM!uido !ue contiene esencialmente benceno puro. El benceno fresco y el recirculado, ambos a 22-', se me9clan en una proporciLn :3, y pasan a travRs de un intercambiador de calor, donde el e>uente del reactor los calienta antes de entrar al reactor. El e>uente del reactor entra a este intercambiador a 0-' y sale a -'. 5a presiLn en el reactor es su7ciente para mantener el e>uente en estado lM!uido. ?espuRs de enfriarse en el intercambiador de calor, el e>uente del reactor entra a una columna de destilaciLn. 8e extrae en la parte superior de la columna todo el butano y el propileno !ue no reaccionL y en la parte inferior de la columna el cumeno y el benceno !ue no reaccionL y entran a una segunda columna de destilaciLn, donde se separan. El benceno !ue sale por la parte superior de la segunda columna es el >u6o de recirculaciLn !ue se me9cla con la alimentaciLn de benceno fresco. 5a velocidad de producciLn del cumeno es lb mhr. a) ;alcula las velocidades de >u6o mSsico de los >u6os !ue alimentan el reactor, la velocidad de >u6o molar y la composiciLn del e>uente del reactor, y la velocidad de >u6o molar y la composiciLn del producto de la parte superior de la primera columna de destilaciLn. b) ;alcula la temperatura del >u6o de benceno !ue alimenta al reactor, y la velocidad de adiciLn o extracciLn de calor del reactor !ue se re!uiere.
c) Bay probabilidad de !ue las aproximaciones !ue se han hecho sobre los datos del proceso o las condiciones dadas no se puedan reali9ar en la prScticaK.
